The invention relates to a glow plug with an integrated pressure sensor for measuring pressure in the combustion chamber of an internal combustion engine, where the shell of the glow plug has a section of reduced diameter on the side of the combustion chamber, which houses a glow coil and ends in a tip protruding into the combustion chamber, the pressure sensor being positioned without cooling in the section of the glow plug adjacent to combustion chamber.
The pressure prevailing in the combustion chamber is an essential variable in studying the combustion process of an internal combustion engine. To implement pressure controlled valve timing efforts are made in order to enable pressure measurement in the combustion chamber. As it is economically not feasible to provide a separate bore or opening into the combustion chamber for the purpose of pressure measurement and as the geometry of the combustion chamber should not be altered, the existing bores for a spark plug or a glow plug should be used for pressure measurement.